The present invention concerns proton conducting polymers and their use as electrolytes in electrochemical devices More specifically, the present invention is directed to polymers which have a proton conductivity and mechanical characteristics that allow them to be used as electrolytes in electrochromic panes; i.e., in panes in which light transmission can be modified by the action of a potential difference, thanks to the presence of a layer of electrochromic material (such as oxides and/or hydroxides of tungsten, iridium, nickel or titanium) which material has the ability to reversibly change color upon the insertion of cations and, notably, of protons.
In order for proton conducting polymers to be effective as electrolytes in electrochemical devices they must fulfill several criteria notably combining good film-forming abilities with both satisfactory compatibility and sufficient bonding with adjacent layers of an electrochromic system. Generally, both for reasons of ease of use and in order to achieve a sufficiently high conductivity, it is necessary for these polymers to be essentially amorphous, as any onset of crystallinity is very unfavorable toward the eventual conductivity of the material, and, further, it is necessary for these polymers to have an elastomeric character which favors mobility of the segments of the polymer network and, accordingly, promotes proton transfer.